Integration of Semiconductor Oxide and a Microporous (3,10)-Connected Co₆-Based Metal–Organic Framework for Enhanced Oxygen Evolution Reaction

Abstract

Developing high-efficiency and cost-effective electrocatalytic oxygen evolution reaction (OER) catalysts would determine the future distributions of energy conversion technologies. Metal-organic frameworks (MOFs), with unsaturated active metal sites, functionalized organic linkers, and large surface areas, are emerging heterogeneous electrocatalysts for the water oxidation process. Herein, we report an oxygen-evolving microporous (3,10)-connected Co₆-based MOF (denoted as CTGU-14) for the electrocatalytic OER. Moreover, the integration of Co-MOF and SnO₂, SnO₂ (15%) & CTGU-14 composite attains remarkable electrochemical OER performance with a small Tafel slope of 68 mV·dec^-1, a positive overpotential of 388 mV at 10 mA·cm^-2, and overall durability in an alkali medium. The superior OER activities might be ascribed to more convenient electron transfer from the SnO₂ additive to the electrode medium, effective surface area and unsaturated active cobalt centers, and more beneficial delivery for hydroxy radicals in the microporous Co-MOF skeleton in the process of the OER.